18 May 2017

O.2.8.5 Development of Optimum Design Method for the Heat Recovery Ground Source Heat Pump System

A method for the design and operation of a heat-recovery ground-source heat pump (HR-GSHP) system has been investigated. In this paper, an optimum design method for the HR-GSHP system was first introduced. By applying the optimum design method, the total heating and cooling loads of each ground-source heat pump (GSHP) unit in the HR-GSHP system were maximized in response to an arbitrarily set total length of the ground heat exchanger (GHEX). This means that the HR-GSHP system designed with the optimum method could yield the maximum energy saving effect for a given GHEX total length. Next, it was assumed that the HR-GSHP system with a 7,200-m total GHEX borehole length was installed in a large scale complex building, which required both heating and cooling at the same time throughout the year, and the hourly heating and cooling loads of each GSHP unit was determined using the optimum design method. As a result, it was confirmed that the HR-GSHP could cover approximately 4.3 times the heat load of a conventional GSHP system. In addition, the simulation of annual HR-GSHP system operation was performed using the design and performance prediction tool for the GSHP system. The hourly heat load determined by the optimum design method was given in the simulation. The average coefficients of performance (COP) for the HR-GSHP system were 4.6 for heating and 10.3 for cooling. Thus, the HR-GSHP system was advantageous in not only the amount of heat load that could be covered but also the COP compared to the conventional GSHP system